Game Development Reference
In-Depth Information
drawn twice, essentially doubling the number of polygons in the scene),
and new visual effects like particles and complex shaders became used
and expected by gamers. As the hardware got more powerful, we simply
asked more of it.
Rules of 3D Game Modeling
So now that we've established that there are indeed limitations to what
computers can show, it's easy to see that limits or rules need to be heeded
when creating assets for unity. We will visit new rules with each step (there are
specific considerations for texturing, for instance, that we won't cover until
later). For this first tutorial, the two rules are:
1.
Polycount matters.
2.
Topology is critical (quads are best).
Polycount Matters
All the dynamic rise in hardware means that the visual sophistication of games
continues to rise at an exciting pace. It also means that carefully creating
our assets to allow for room to create these great effects remains the reality.
Ultimately, effective use of the number of polygons in a scene (
polycount
)
will be critical to both the immersive impact of the game and conversely, the
performance in frame rate at which the game will play. Now, with most recent
machines, polycount is much less of an issue than it once was. And frankly, usually
if a game is dog-slow, it isn't a case of the sheer number of polys—it's usually
related to other texture problems or other issues related to
draw calls
(more on
this later). However, keeping an eye on the number of polys in your scene remains
one of the pressures on a video card, and keeping a reasonable poly-budget is
important (especially if ultimately developing for any mobile devices).
This can sometimes be a tricky balance.
Figure 2.3
shows two sphere-like objects.
The one on the right has 1000 polygons and the one on the left has 20. Sure
enough, the 20-polygon model will require less video card power to draw, but it
really doesn't appear to be a sphere anymore. Carefully dialing the details up to
effectively communicate the shape while keeping the number of polygons low
enough to draw quickly is part of the art that is game asset creation.
Figure 2.3
Varying polycounts can
widely change the draw on a video
card, but optimized too much moves
away from the form.
